A ski binding part is known which has swingably supported two-arm levers. The shorter lever arms engage a so-called stroke reducer. This is a part onto which the spring acts and which is movable transversely of the direction of action of the spring, whereby inclined surfaces of the shorter lever arms slide on inclined surfaces of the stroke reducer. Such a construction is not only very expensive, but also easily susceptible to trouble. Furthermore, very high frictional forces occur between the movable stroke reducer, support with respect to the spring and the inclined surfaces of the lever arms. It must also be added that the ski boot, during a safety release, must practically force itself from the binding, because the spring force increases constantly with the increasing angle of traverse of the sole holder lever. Through this, there exists also the danger that the ski boot is jammed in a pivoted position.
Furthermore a ski binding part is known, which also engages the ski boot sole with two-arm levers. The shorter lever arms each carry a locking element, which is engaged by each one locking member which is loaded by a separate or by a common spring. In the one embodiment, two locking members, two locking springs and two adjusting screws are thus required in an expensive manner. A disadvantage must be mentioned at this point in that the release force of each lever must be adjusted separately and these two adjustments can be tuned with respect to one another only with great difficulty. In the case of the common spring load, the adjustment is possible with one single adjusting element, however, due to the construction, a so-called spring stack must be used, which consists of several leaf springs. This leaf spring stack loads two swingable levers, which carry the locking members, and engage the locking elements of the two-arm sole holder levers. Thus, the prior art deals with clearly expensive constructions which are complicated and, therefore, easily susceptible to trouble.